Cow's milk dependent exercise-induced urticaria after oral tolerance induction in an adolescent

Introduction

To the Editor, Exercise-induced urticaria (EIU) is a clinical syndrome in which urticaria occurs in association with exercise.¹ EIU may occur independently of food or may require the ingestion of a food allergen prior to exercise, in a process of food dependent exercise-induced urticaria (FDEIU). During oral tolerance induction (OTI) to cow's milk (CM) in allergic children, many factors have been pointed out as being responsible for a higher risk of allergic reactions with CM doses previously tolerated, being exercise the most common one.² However, prospective data concerning this subject after ending OTI are still lacking. We report the case of a 16-year-old male, referred to our Immunoallergy department in 2002, at the age of eight years, reporting an IgE-mediated cow's milk allergy (CMA) diagnosed at four months of age following an episode of anaphylaxis. Since then he began strict allergen avoidance, although he has experienced four anaphylactic reactions by accidental ingestion of hidden CM. He also reported intermittent asthma and persistent rhinitis plus family history of atopy. Skin prick tests (SPT) were positive to grass pollens, whole CM, casein, α-lactoalbumin and β-lactoglobulin (Laboratorios Leti, Madrid, Spain). Total IgE was 262kU/L and sIgE to whole CM 47kU/L, casein 51 kU/L, α-lactoalbumin 9 kU/L and β-lactoglobulin 2 kU/L, and increased throughout the years, reaching 350 kU/L to whole CM in 2005 (Phadia, Uppsala, Sweden). Oral food challenges were regularly performed to evaluate tolerance, and consecutively caused anaphylaxis; the last one, at 11 year-old, was positive with 10mL. Because of this persistency, we decided to start...